1. Field of the Invention
The present invention relates to a folding portable cellular phone having a function of detecting its folding state.
The present application claims priority of Japanese Patent Application No. 2001-055201 filed on Feb. 28, 2001, which is hereby incorporated by reference.
2. Description of the Related Art
Devising and developing work on configurations and functions of a portable cellular phone is proceeding in order to meet an increasing need for making the portable phone smaller and more lightweight and for enhancing its usability. One example of a result from such efforts is a folding portable cellular phone which can be folded by a division of a phone body into two portions, thereby enabling it to fit into a bag or pocket and therefore improving its portability.
There are some folding portable cellular phones which have a function of detecting their folding state. This kind of the folding portable cellular phone, while being folded, automatically stops a supply of power to a displaying section such as a liquid crystal display (LCD) and/or to each part of circuits (except some circuits such as a timer circuit or a like) to reduce power consumption and, immediately after it is opened, the phone lights up its displaying section and starts operations of its circuits.
In order to detect the folding state of phone bodies, in some cases, a magnet is incorporated in one phone body which is coupled to an other phone body by using, for example, a hinge and a lead switch adapted to operate in response to a magnetic flux of the magnet attached to the other phone body. In other cases, a mechanical switch is attached to one phone body being also coupled to an other phone body and a protrusion portion adapted to push the mechanical switch with pressure is formed on the other phone body.
However, such the conventional folding portable cellular phone has a problem. That is, in the folding portable cellular phone using the magnet and lead switch as a means for detecting the folding state of the phone bodies, to ensure operations of the lead switch, a magnet having the intensity of a magnet field exceeding a level is required and therefore the magnet having such a high intensity of the magnet field affects circuit components and/or acoustic components in the phone body in some cases. For example, a vibration caused by sound signals and magnetic force occurs in the vicinity of a microphone and/or receiver of the portable cellular phone, which causes a phenomenon in which the microphone picks up the vibration and outputs it as a voice to a party on the other end of the phone and a noise is output from the receiver. On the other hand, in the folding portable cellular phone using the mechanical switch and the protrusion as a means for detecting the folding state, when the phone body is dropped on a floor, the protrusion portion is easily broken, causing the detecting operation to become impossible.